The application is related to new surface glycoproteins of human myeloma cells and human ovarian tumor cells, monoclonal antibodies thereto, and methods of diagnosis and treatment of myeloma and ovarian cancer based thereon.
Multiple myeloma (MM) embodies a plasma cell disorder characterized by neoplastic proliferation of a single clone of plasma cells engaged in the production of a monoclonal immunoglobulin, usually monoclonal IgG or IgA. MM accounts for 1% of all malignant disease and slightly more than 10% of all hematologic malignancies. The annual incidence of multiple myeloma is 4 per 100,000. The annual incidence is linked to aging population. The median age of patients at the time of diagnosis is 61 years. MM is most common in men, and in individuals of African ancestry.
MM remains a disease for which a cure is a rarity. Most patients succumb to their disease within 36-48 months from the time of diagnosis. The limitations of effective therapy for MM are primarily associated with the low cell proliferation rate and multi-drug resistance. Therapy for multiple myeloma includes induction, maintenance, and supportive aspects. The induction portion of the treatment aims at reducing the tumor volume, and achieving a plateau phase. Different drugs, and treatment modalities such as bone marrow transplantation has been entertained, and used without a significant impact on the disease or the overall survival. Supportive care in multiple myeloma has advanced significantly over the past few years. Growth factor support with erythropoietin replacement and GM-CSF for stimulating the WBC is a safe and effective method of decreasing or preventing the occurrence or the severity of neutropenia. Also high dose chemotherapy followed by autologous bone marrow or peripheral blood progenitor cell (PBMC) transplantation has recently increased the complete remission rate and remission duration. However, overall survival has only been slightly prolonged, and no evidence for a cure has been obtained. All patients ultimately relapse even under maintenance therapy with interferon-xcex1 (IFN-xcex1) alone or in combination with steroids. Adoptive immunotherapy rather than active vaccination may prove to be a more effective therapy for MM patients. There are relatively known few surface antigens on the plasma cells that are suitable for antibody-directed treatment. Possible molecules include HM1.24, CD38, ICAM-1 (CD54), CD40, CD45, CD20, and syndecan 1.
To-date there are no exclusive markers reported for MM. CD20, CD38, CD56 and CD130 are all markers that are expressed on normal B, T or NK cells.
Ovarian cancer is the fifth leading cause of cancer deaths among U.S. women and has the highest mortality of any of the gynecologic cancers. It accounted for an estimated 26,600 new cases and 14,500 deaths in 1995. The overall 5-year survival rate is at least 75% if the cancer is confined to the ovaries and decreases to 17% in women diagnosed with distant metastases. Symptoms usually do not become apparent until the tumor compresses or invades adjacent structures, ascites develops, or metastases become clinically evident. As a result, two thirds of women with ovarian cancer have advanced (Stage III or IV) disease at the time of diagnosis. Carcinoma of the ovary is most common in women over age 60. Other important risk factors include low parity and a family history of ovarian cancer. Less than 0.1% of women are affected by hereditary ovarian cancer syndrome, but these women may face a 40% lifetime risk of developing ovarian cancer.
Potential screening tests for ovarian cancer include the bimanual pelvic examination, the Papanicolaou (Pap) smear, tumor markers, and ultrasound imaging. The pelvic examination, which can detect a variety of gynecologic disorders, is of unknown sensitivity in detecting ovarian cancer. Although pelvic examinations can occasionally detect ovarian cancer, small, early-stage ovarian tumors are often not detected by palpation due to the deep anatomic location of the ovary. Thus, ovarian cancers detected by pelvic examination are generally advanced and associated with poor survival. The pelvic examination may also produce false positives when benign adnexal masses (e.g., functional cysts) are found. The Pap smear may occasionally reveal malignant ovarian cells but it is not considered a valid screening test for ovarian carcinoma. Ultrasound imaging has also been evaluated as a screening test for ovarian cancer, since it is able to estimate ovarian size, detect masses as small as 1 cm, and distinguish solid lesions from cysts.
Serum tumor markers are often elevated in women with ovarian cancer. Examples of these markers include carcinoembryonic antigen, ovarian cystadenocarcinoma antigen, lipid-associated sialic acid, NB/70K, TAG 72.3, CA15-3, and CA-125. respectively. Evidence is limited on whether tumor markers become elevated early enough in the natural history of occult ovarian cancer to provide adequate sensitivity for screening. Tumor markers may have limited specificity. It has been reported that CA-125 is elevated in 1% of healthy women, 6-40% of women with benign masses (e.g., uterine fibroids, endometriosis, pancreatic pseudocyst, pulmonary hamartoma), and 29% of women with nongynecologic cancers (e.g., pancreas, stomach, colon, breast). Prospective studies involving asymptomatic women are needed, however, to provide definitive data on the performance characteristics of serum tests when used as screening tests.
In its broadest aspect, the present invention is directed to a monoclonal antibody or binding fragment thereof which specifically binds to antigens sharing a common epitope present on the surface of human myeloma cells and ovarian cancer cells. The antigen on multiple myeloma cells is a single, glycosylated polypeptide with a molecular weight of about 78 kDa to about 120 kDa as determined by SDS PAGE under reducing conditions. The antigen on ovarian cancer cells is a single, glycosylated polypeptide with a molecular weight of about 76 kDa to about 213 kDa as determined by SDS PAGE under reducing conditions. The antigens are absent from human peripheral blood mononuclear cells, absent from human B cells, and absent from human chronic myelogenic leukemia cells. A non-limiting example of the monoclonal antibody is that produced by the hybridoma cell line deposited at the American Type Culture Collection having accession No. PTA-450. Furthermore, the antigens are not present on cells from a breast cancer tumor, not present on a prostate cancer cell line, not present on a neuroblastoma cells line, and not present on a cervical cancer cell line. They are also not found on an Epstein-Barr virus-transformed B cell tumor.
The present invention is further directed to antibodies that are capable of binding to the same antigenic determinant as does the monoclonal antibody produced by the hybridoma cell line deposited at the American Type Culture Collection having accession No. PTA-450; binding fragments of the hybridoma cell line deposited at the American Type Culture Collection having accession No. PTA-450; and to binding fragments of a monoclonal antibody capable of binding to the same antigenic determinant as does the monoclonal antibody produced by the hybridoma cell line deposited at the American Type Culture Collection having accession No. PTA-450.
Such monoclonals or fragments may be human, or may be of other mammalian species such as rodent, hybrids thereof, chimeric antibodies, and the like. Binding fragments of the monoclonal antibodies of the present invention include but are not limited to F(abxe2x80x2)2, Fabxe2x80x2, Fv, Fdxe2x80x2, or Fd fragments.
In another aspect, the present invention is directed to a cell line produced by a hybridoma technique, which produces a monoclonal antibody which specifically binds to surface antigens of human myeloma cells and of ovarian cancer cells. The antigen on multiple myeloma cells is a single, glycosylated polypeptide with a molecular weight of about 78 kDa to about 120 kDa as determined by SDS PAGE under reducing conditions. The antigen on ovarian cancer cells is a single, glycosylated polypeptide with a molecular weight of about 76 kDa to about 213 kDa as determined by SDS PAGE under reducing conditions. The antigens are absent from human peripheral blood mononuclear cells, absent from human B cells, and absent from human chronic myelogenic leukemia cells. A non-limiting example of the monoclonal antibody is that produced by the hybridoma cell line deposited at the American Type Culture Collection having accession No. PTA-450. Furthermore, the antigens are not present on cells from a breast cancer tumor, not present on a prostate cancer cell line, not present on a neuroblastoma cells line, and not present on a cervical cancer cell line. They are also not found on an Epstein-Barr virus-transformed B cell tumor.
A further aspect of the present invention is the hybridoma cell line deposited at the American Type Culture Collection having accession No. PTA-450.
In another broad aspect of the present invention, an isolated surface antigen of human multiple myeloma cells is described, the antigen being a single, glycosylated polypeptide with a molecular weight of about 78 kDa to about 120 kDa as determined by SDS PAGE under reducing conditions; the antigen being absent from human peripheral blood mononuclear cells, absent from human B cells, and absent from human acute myelogenic leukemia cells. The antigen is not present on cells from a breast cancer tumor, not present on a prostate cancer cell line, not present on a neuroblastoma cells line, and not present on a cervical cancer cell line. It is also not found on an Epstein-Barr virus-transformed B cell tumor. The isolated multiple myeloma surface antigen binds to a monoclonal antibody produced by the hybridoma cell line deposited at the American Type Culture Collection having accession No. PTA-450.
In another broad aspect of the present invention, an isolated surface antigen of human ovarian cancer cells is described, the antigen being a single, glycosylated polypeptide with a molecular weight of about 76 kDa to about 213 kDa as determined by SDS PAGE under reducing conditions; the antigen being absent from human peripheral blood mononuclear cells, absent from human B cells, and absent from human acute myelogenic leukemia cells. The antigen is not present on cells from a breast cancer tumor, not present on a prostate cancer cell line, not present on a neuroblastoma cells line, and not present on a cervical cancer cell line. It is also not found on an Epstein-Barr virus-transformed B cell tumor. The isolated ovarian cancer surface antigen binds to a monoclonal antibody produced by the hybridoma cell line deposited at the American Type Culture Collection having accession No. PTA-450.
The present invention is also directed to methods for inhibiting or killing myeloma cells in a patient by administering the monoclonal antibody or binding fragment as described above under conditions sufficient for the binding of the monoclonal antibody or binding fragment to the myeloma cells to cause inhibiting or killing of the cancer cells by the immune cells of the patient. In another aspect, a method for inhibiting or killing myeloma cells in a patient is provided by administering the monoclonal antibody or binding fragment as described above which is conjugated with a cytotoxic moiety, under conditions sufficient for the binding of the monoclonal antibody or binding fragment to the cancer cells to cause inhibiting or killing of the cells. The cytotoxic moiety may be, by way of non-limiting example, a chemotherapeutic agent, a photo-activated toxin or a radioactive agent.
In still another aspect of the invention, the above-mentioned conjugate of the monoclonal antibody or binding fragment described herein and a cytotoxic moiety may be used in vitro to inhibit or kill myeloma cells in a cellular sample, such as a bone marrow sample.
The invention is also directed to anti-idiotypic antibodies which mirror the binding site of the monoclonal antibody of the invention, and arc specific to the myeloma and ovarian cancer conformational epitope recognized by the antibody of the invention. The invention is further directed to the use of the aforementioned anti-idiotypic antibodies for the treatment of MM or ovarian cancer by active immunization.
In a further aspect of the invention, a method is provided for removing myeloma cells from an isolated cellular sample, such as, but not limited to, bone marrow cells, by exposing the cellular sample to a solid matrix on which the monoclonal antibody or binding fragment described above is bound under conditions wherein the myeloma cells adhere to the monoclonal antibody or binding fragment, and isolating a cellular fraction of said cellular sample which does not bind to the matrix. This method may be used, for example, in the removal of myeloma cells from a bone marrow sample for autologous bone marrow transplant.
The invention is also directed to the monoclonal antibody or binding fragment as described above bound to a solid support.
In yet another aspect of the invention, a method is provided for localizing myeloma cells or tumors, or ovarian cancer cells or tumors, in a patient by administering the monoclonal antibody or binding fragment described above, allowing the monoclonal antibody or binding fragment thereof to bind to the cancer cells within said patient, and determining the location of the monoclonal antibody or binding fragment thereof within the patient. In another related aspect, the monoclonal antibody or binding fragment is detectably labeled, for example, with a radionuclide.
The present invention is further directed to methods for inhibiting or killing ovarian cancer cells in a patient by administering the monoclonal antibody or binding fragment as described above under conditions sufficient for the binding of the monoclonal antibody or binding fragment to the ovarian cancer cells to cause inhibiting or killing of the ovarian cancer cells by immune cells of the patient. In another aspect, a method for inhibiting or killing ovarian cancer cells in a patient is provided by administering the monoclonal antibody or binding fragment as described above which is conjugated with a cytotoxic moiety, under conditions sufficient for the binding of the monoclonal antibody or binding fragment to ovarian cancer cells to cause inhibiting or killing of the ovarian cancer cells. The cytotoxic moiety may be, by way of non-limiting example, a chemotherapeutic agent, a photo-activated toxin or a radioactive agent.
In yet another aspect of the invention a method is provided for localizing ovarian cancer cells in a patient by administering the monoclonal antibody or binding fragment described above, allowing the monoclonal antibody or binding fragment thereof to bind to ovarian cancer cells within said patient, and determining the location of said monoclonal antibody or binding fragment thereof within said patient. In another related aspect, the monoclonal antibody or binding fragment is detectably labeled, for example with a radionuclide.
It is a further aspect of the invention to permit the detection of the cell surface glycoproteins described herein in a sample of bodily fluid, to aid in the diagnosis of multiple myeloma, ovarian cancer, or other cancer cells expressing a glycoprotein with the epitope recognized by the antibodies herein by the detection of the glycoprotein antigen shed from cancer cells into the bodily fluid, such as blood. Furthermore, the state of the disease may be monitored and the effectiveness of anticancer therapies monitored by determining the level or changes over time of the level of shed surface glycoprotein in a bodily fluid such as blood.
In still yet another aspect, the invention is directed to pharmaceutical compositions comprising a monoclonal antibody or binding fragment as described above, and a pharmaceutically-acceptable carrier or diluent.
In another aspect, the present invention is directed to a monoclonal antibody or binding fragment as described above labeled with a detectable moiety, such as, by way of non-limiting examples, a fluorophore, a chromophore, a radionuclide, or an enzyme.